The distal radius is one of the most common sites of bone fracture and is the most common fracture site in the upper extremity, accounting for approximately 10% of all fractures in adults. Approximately 25% of patients (~80,000/year) require surgery to correctly repair this bone, and current practice requires the surgeon to disrupt the soft tissues surrounding the joint to expose the bone for placement of hardware to stabilize the fracture. Thus, improved joint stability is achieved by sacrificing the integrity of an extensie tendon, ligament and neuromuscular network that is needed for proper wrist function. EndoOrthopaedic's core technology is a universal system of trans-cortical, micro-adjustable bone implants (TABI) for intramedullary fixation that can be assembled by the surgeon entirely within a fracture to restore the shape of the articulating surfaces. Adaptation of our TABI device for intramedullary fracture fixation of the distal radius would provide orthopaedic surgeons with a valuable option in the treatment of distal radial fractures. The device is designed to be deployed during a minimally invasive surgery, thereby reducing the cost of each surgery and minimizing the risk associated with soft tissue damage during the procedure. Also, since the device is completely intramedullary, it will not interfere with the soft tissues after the fracture has heale, which will substantially reduce the need for revision surgeries. For these reasons, the TABI device will lead to an overall reduction in the costs associated with treatment of distal radial fractures. In Phase I of this project, we demonstrated that our device was sufficient to resist interfragmentary strains in distal radial fractures during habitual loading and could prevent re-fracture during periodic overloading. During Phase II, our overall objective is to evaluate the mechanical performance of specific TABI device features that are designed to enable an efficient implantation procedure. We will thus validate the number of surgical steps required to implant the TABI device with the following specific aims: (1) to measure the implantation force of the intramedullary pins to verify sufficient haptic feedback for intuitive deployment by the surgeon; (2) to validate the strength of intramedullary pin attachment to a central hub, and (3) to demonstrate the surgical efficiency and mechanical performance of the TABI device. At the conclusion of our Phase II study, we will have validated the mechanical properties and surgical implantation procedure for the EndoOrthopaedics TABI device. As we conclude this project, we will translate our study results into regulatory documents that we will use when seeking FDA approval to market our TABI fixation technology.